10 juin 1752 - Invention of Bifocals
Description:
In 1752, Benjamin Franklin invented bifocals. Bifocals are glasses with transitional lenses that allow people who are both farsighted and nearsighted to maintain their vision with one pair of glasses, and while they have been upgraded, they are still used today.Ajouté au bande de temps:
Date:
10 juin 1752
Maintenaint
~ Il y a 273 ans